A standardized YUV video system represents video information using a luminance component (Y) and a two-dimensional chromaticity component (UV). Such representations are sometimes called chromaticity spaces. The YUV system was designed to allow measurement of color differences, and exhibits a correlation between, "distance" computed from coordinate differences and subjective color differences reported by observers.
In some computer systems, digital video signals are provided as streams of ten-bit YUV values: a ten-bit value for Y. the luminance component; a ten-bit value for the U portion of the two-dimensional chromaticity component, and a ten-bit value for the V portion of the two-dimensional chromaticity component.
In many computer video-graphics adaptors, eight-bit values are used for representing colors. Such systems often use three color values for a total of 24 bits representing the color of each pixel.
For speed, cost, and convenience it would be desirable to present digital video in eight-bit quantities, but at the same time preserve subjective qualities of the video signal. Therefore, there is a need for a circuit and method for compressing 10-bit video streams for display through an 8-bit VGA video port of a computer.